BS ISO/IEC 10028-1993 信息技术.系统间通信和信息交换.网络层中间系统的中继功能定义

标准号：BS ISO/IEC 10028-1993
中文标准名称：信息技术.系统间通信和信息交换.网络层中间系统的中继功能定义
英文标准名称：Information technology - Telecommunications and information exchange between systems - Definition of the relaying functions of a network layer intermediate system
标准类型：L79
发布日期：1994/3/15 12:00:00
实施日期：1994/3/15 12:00:00
中国标准分类号：L79
国际标准分类号：33.040.40;35.110
适用范围：This International Standard defines the abstract operation of the relaying functions of a Network entity in an intermediate system, as needed to support the OSI connection-mode Network service. As the principal means for expressing the definition, the concept of the Network Internal Layer Service is used. This is similar to an OSI layer service, but adapted to expressing the invariants of the information flow within and throughout the layer, rather than just the external functionality of the layer provided between two service access points. The definition includes the invocation of Network routing functions as a necessary element of the Network relaying functions, but it does not specify how those routing functions are to be realized. The definition of Network relaying functions applies both to a subnetwork supporting all elements of the Network Service (as defined in ISO 8648), and to a Network relay system interconnecting two subnetworks according to any of the three approaches defined in ISO 8648. In the case of the hop-by-hop harmonization approach to interconnection, the definition of Network relaying functions applies to the result of harmonizing the subnetwork service(s) to the level of the Network Service. The harmonization functions, which require protocol mechanisms to be specified, are outside the scope of this International Standard. This International Standard is intended for use in guiding the design and application of real interworking units and real subnetworks (eg, local area networks and private packet switched networks) which are to support the OSI NS. It is also intended for use in the development of standards for the Network layer, to ensure that the requirements deriving from the need for Network layer relaying are taken into account. There are no requirements for conformance to this International Standard. NOTE —Conformance requirements relating to Network layer relaying are to be found in the specifications for mappings between the Nctwork Internal Layer Service and Network protocols.